If you've started using the beta of Firefox 3, you've probably already seen the new Smart Bookmarks folder that is created by default. This folder can be useful for looking up sites you just visited or bookmarked… but how do you get it back if you accidentally deleted it?Luckily there's a simple about:config tweak that will restore it, requiring almost no work at all.In case you aren't sure what we're talking about, here's the default Smart Bookmarks folder, which dynamically shows you the "Most Visited", "Recently Bookmarked" and "Recent Tags" bookmarks:

Type about:config into the address bar, accept the warning message, and then filter by the following:browser.places.createdSmartBookmarks

You should see a single entry in the list with a default value of true. Double-click on it to set the value to false, restart Firefox, and your Smart Bookmarks folder is now back: